The present invention relates to a roller for rolling an electrode composite plate of an electrical storage cell, and more particularly, to a roller for rolling an electrode composite plate having a heater to easily control the thickness of the electrode composite plate and to easily perform winding during rolling of the electrode composite plate.
An electrode composite plate 10 which is wound into a roll, as shown in FIG. 1, is installed inside a cylindrical case (not shown) of a cylindrical storage cell such as a nickel-hydrogen storage cell. The electrode composite plate 10 includes an anode electrode plate 11, a cathode electrode plate 12, and an insulating separator 13 disposed between the electrode plates 11 and 12.
The above electrode composite plate 10, as shown in FIG. 2, is manufactured by rolling and winding a plurality of rollers 21. The electrode composite plate 10 is pressed by the rollers 21, rolled to an appropriate thickness and then wound.
Active material layers (not shown) coated on the anode and cathode electrode composite plates 11 and 12 (FIG. 1) may crack or break during the performance of the above operations, thus deteriorating the performance and life of the cell. Such cracking and breaking are caused by the uneven speeds at which the electrode composite plate 10 is wound and at which the electrode composite plate 10 is supplied. The cracking and breaking is more severe as the winding diameter of the electrode composite plate 10 increases. In particular, when there is a difference in the speed at which the electrode composite plate 10 is supplied and the speed at which the electrode composite plate 10 is wound, different stresses are distributed in the respective portions of the electrode composite plate 10. Consequently, wrinkled or elongated portions may be generated due to the difference in stress distribution. It is hard to compensate for such non-uniform portions during rolling.
Also, the thickness of the electrode composite plate 10 should be controlled to be less than a certain range in order to increase the capacity of the cell and the overall thickness of the electrode composite plate 10 should be uniform by rolling of the electrode composite plate 10. If the thickness of the electrode composite plate 10 varies at different portions, the cracking and breaking of the active material becomes more serious during winding the electrode composite plate 10 and the electrode composite plate 10 cannot be tightly wound, thus reducing the capacity of the cell.
Means for correcting the difference of the stress distribution and facilitating control the thickness of the electrode composite plate are not provided in a conventional roller for rolling an electrode composite plate for a cell.